1. Field of the Invention
The invention relates generally to food, beverage, and personal care product additives and, more specifically, to finely dispersed carotenoid suspensions for use in supplementing foods, beverages, and personal care products with carotenoids, for use in coloring foods and beverages, and to a process for their preparation.
2. Background of the Prior Art
Carotenoids are naturally-occurring yellow to red pigments of the terpenoid group that can be found in plants, algae, and bacteria. Carotenoids include hydrocarbons (carotenes) and their oxygenated, alcoholic derivatives (xanthophylls). They include actinioerythrol, astaxanthin, bixin, canthaxanthin, capsanthin, capsorubin, xcex2-8xe2x80x2-apo-carotenal (apo-carotenal), xcex2-12xe2x80x2-apo-carotenal, xcex1-carotene, xcex2-carotene, xe2x80x9ccarotenexe2x80x9d (a mixture of xcex1- and xcex2-carotenes), xcex3-carotene, xcex2-cryptoxanthin, lutein, lycopene, violerythrin, zeaxanthin, and esters of hydroxyl- or carboxyl-containing members thereof. Many of the carotenoids occur in nature as cis- and trans-isomeric forms, while synthetic compounds are frequently racemic mixtures. The carotenes are commonly extracted from plant materials. For example, lutein extracted from marigold petals is widely used as an ingredient in poultry feed where it adds color to the skin and fat of the poultry and to the eggs produced by the poultry. Many of the carotenes are also made synthetically; much of the commercially available xcex2-carotene has been made through synthesis.
Carotenoids are used in the pharmaceutical industry and as ingredients in nutritional supplements, most commonly to date because of their pro-vitamin A activity. They have been extensively studied as antioxidants for protection against cancer and other human and animal diseases. Among the dietary carotenoids, the focus has been on xcex2-carotene. More recently, research has begun to elicit the broad role that other carotenoids play in human and animal health. The xanthophylls in particular have been shown to possess strong antioxidant capabilities and may be useful in reducing the risk of disease. For example, the consumption of lutein and zeaxanthin has been identified as leading to a 57 percent reduction in age-related macular degeneration (Seddon et al., 1994. J. Amer. Med. Assoc. 272(18): 1413-1420). Lycopene has been identified as a nutrient that is active in reducing the risk of prostate cancer.
Carotenoids have also been of wide interest as a source of added color for food and drink products and many efforts have been made to attempt to use them as xe2x80x9cnaturalxe2x80x9d colorants for foods and beverages. However, their insolubility in water, their low solubility in fats and oils, high melting points, and their sensitivity to oxidation has limited their use, particularly in water-based products such as beverages and juices and products to which water is to be added.
Current processes for incorporating carotenoids into water-based beverages or foods involve the use of organic solvents, oils with emulsifiers, high heating, or high-shear mixing. Many of the current processes, particularly in beverages, produce a deposit of the carotenoids around the perimeter of the container in the region of the surface of the treated food or beverage, known as xe2x80x9cringing.xe2x80x9d Optical clarity is a critical characteristic for many beverage compositions. Various fruit drinks, fruit juices and fortified water drinks have included terms such as xe2x80x9ccrystal clearxe2x80x9d and xe2x80x9cfreshxe2x80x9d to distinguish their image and marketability. Traditionally, this clarity has been difficult to achieve when carotenoids are added to these aqueous compositions. The use of emulsifiers and oil for the incorporation of carotenoids will commonly result in cloudiness of the final aqueous composition.
In U.S. Pat. No. 3,998,753, a dispersible carotenoids product is made by forming a solution of carotenoids and a volatile organic solvent and emulsifying the solution with an aqueous solution containing sodium lauryl sulfate using high speed mixing with high shear. The volatile solvent is removed by heating the emulsion while maintaining the high speed mixing with high shear.
In U.S. Pat. No. 5,532,009, a powdered water soluble xcex2-carotene composition is prepared by initially forming an aqueous solution of cyclodextrin. The solution is heated to between 45 and 95xc2x0 C. Separately, xcex2-carotene is dissolved in an organic solvent to form a supersaturated solution of xcex2-carotene. The xcex2-carotene solution is added to the hot cyclodextrin solution with rapid stirring. Upon drying, the powders are added to non-digestible fats, including polyol fatty acid polyesters and poly glycerol esters.
In U.S. Pat. No. 5,607,707, an antioxidant is dispersed in an emulsifier while heating to 40xc2x0 C. The carotenoid is then added and the temperature is raised to between 80 and 200xc2x0 C. while stirring. The mixture is then added to water (at least 95xc2x0 C.) while stirring.
In U.S. Pat. No. 5,895,659, carotenoid suspensions are prepared by dissolving the carotenoid in a volatile, water-miscible organic solvent at preferably between 150 and 200xc2x0 C. within less than 10 seconds and immediately thereafter mixing the solution with an aqueous medium at from 0 to 90xc2x0 C. An emulsifier is present either in the organic solvent or the aqueous medium or both.
The present invention involves the dispersion of carotenoids into water-based systems, such as food, beverages and personal care products. A carotenoid-containing product for addition to these water-based systems is prepared by adding an emulsifier to water. A small quantity of a food-grade alcohol may be added to reduce viscosity. An antioxidant may be added to help in preventing oxidation of the carotenoid. An anti-foaming agent may be added to decrease foaming of the water and emulsifier during processing of the product and during processing of a food or beverage incorporating the product. The carotenoid is then added while mixing. No elevated temperatures, high-shear mixing, or organic solvents are required to form the product.
In a preferred embodiment of the invention, the emulsifiers are selected from cationic, anionic, and non-ionic emulsifiers having a hydrophilic/lipophilic balance (HLB) of between about 12 and about 20, and preferably between about 15 and 18. Examples of suitable emulsifiers include sucrose fatty acid esters (SFAE) and poly glycol esters (PGE). The SFAE and PGE emulsifiers are preferred also because they have very little taste. Emulsifiers may be used singly or in combination; in particular, emulsifiers having diverse HLB numbers may be advantageously used in combination with each other. The amount of emulsifier in the composition is selected as an amount which will vary depending upon which form of carotenoid is used, its method of preparation, and how much is included. For example a dispersion of lutein in oil will require a higher concentration of emulsifier or blend of emulsifiers to disperse the oil and the carotenoid than the corresponding quantity of crystalline lutein.
The water and emulsifier mixture, under certain circumstances, may become too viscous for efficient processing. In these circumstances, a food grade alcohol, such as ethanol, may be added to reduce the viscosity. It is preferred that no more than about 4 weight percent alcohol be used. In commercial processing of the product of the present invention, it is greatly preferred not to include the alcohol in the mixture since it adds a flammable substance to an otherwise non-flammable mixture and thus creates safety issues which add substantially to the costs associated with carrying out the process.
Any suitable commercially available anti-foam agent may be added to the mixture. Examples of suitable anti-foam agents include Silicone AF-100 FG (Thompson-Hayward Chemical Co.), xe2x80x98Transxe2x80x99 Silicone Antifoam Emulsion (Trans-Chemco, Inc.), and 1920 Powdered Antifoam (Dow Corning Chemical). The amount of the anti-foam agent added is kept to the minimum required to prevent excessive foaming during processing of the product and, if desired by the consumer of the product, to prevent excessive foaming during processing of the food or beverage into which the product is being incorporated. Amounts of the anti-foam agent between 1 ppm and up to about 10 ppm in the final product are to be used.
It may be desired to incorporate an antioxidant into the mixture to assist in the prevention of oxidation of the carotenoid so as to preserve its color and activity. Antioxidants known for use in stabilizing carotenoids include tocopherols, extracts of rosemary, ascorbyl palmitate, citric acid, ascorbic acid, BHA, and BHT.
Carotenoids suitable for use in the product include actinioerythrol, astaxanthin, bixin, canthaxanthin, capsanthin, xcex2-8xe2x80x2-apo-carotenal (apo-carotenal), xcex2-12xe2x80x2-apo-carotenal, xcex1-carotene, xcex2-carotene, xe2x80x9ccarotenexe2x80x9d (a mixture of xcex1- and xcex2-carotenes), xcex3-carotene, xcex2-cryptoxanthin, lutein (a xanthophyll), lycopene, violerythrin, zeaxanthin, and esters of hydroxyl- or carboxyl-containing members thereof. Preferably, the carotenoids are in crystalline form. Examples of crystalline carotenoids which can be used in the practice of this invention include lutein, xcex2-carotene, xcex2-cryptoxanthin, xcex1-carotene, lycopene, astaxanthin, canthaxanthin, and zeaxanthin. The carotenoids may be incorporated individually or in combination. The carotenoids are added in an amount to create a concentrated product having between about 1 weight percent and about 20 weight percent carotenoid(s). When the concentrated product is added to a food or beverage product, the levels of carotenoid present in the final product are between about 0.1 mg and 5 mg per serving, depending on the color desired or the level of supplementation of the carotenoid(s), or both. In a beverage, a preferred range is between about 0.2 mg and 1.5 mg per 8 oz.
The concentrated product of the present invention is a dispersion of the carotenoid in the water and emulsifier mixture. The concentrated product, upon visual examination, has the appearance of being a dispersion of discrete crystals of the carotenoid. Microscopic examination clearly shows individual crystals. Upon addition of the concentrated product to a food or beverage, the carotenoid is more finely dispersed and individual crystals are no longer visible. The concentrated product, if desired, may be incorporated into beverages to yield a beverage that is optically clear. The term xe2x80x9coptically clearxe2x80x9d is used to describe a product exhibiting a percentage transmittance value of between about 95% and about 100%, determined at a wavelength of 800 nm in a 1 cm path length cuvette. The optical clarity of the finished products obtainable with the present invention indicate that the carotenoids are finely dispersed as micelles or as microemulsions. This fine dispersion of carotenoids in aqueous preparations may help to promote the efficient uptake of such materials by body tissues when the composition is presented to the body. Moreover, the presence of the emulsifier is also believed to assist in the efficient transfer of these substances across cellular membranes. While the present invention is particularly suited to the production of optically clear products, the present invention can also be used to prepare opaque, cloudy products, specifically juices, soups, sauces, and syrups. The invention is also suitable for use as an additive to fortified foods, such as ready-to-eat cereals, sports and nutrition bars, bread, and the like.
The dispersions of the carotenoids created by the present invention, whether in the concentrated product or in the finished composition, are substantially stable. No ringing of the carotenoids is observed after storage in excess of 7 days at reduced, ambient, and elevated temperatures. Repeated chilling and heating of the product did not reveal any changes in its physical characteristics. The stability of the carotenoid products also makes them attractive as colorants and additions to personal care products which have an aqueous phase, such as lotions, emollients, sun screens, and the like.
The products of the present invention are more economical than other compositions which attempt to obtain similar results, specifically in that no organic solvents are required, no heating is required, no high speed or high-shear mixing is required, and a relatively small amount of emulsifiers are required. The products are therefore also simpler to formulate and manufacture than those already known for the incorporation of carotenoids into drinks and can be used to give a wider range of products, particularly reduced fat and no-fat products.
It is an object of the present invention to provide a finely dispersed carotenoid suspension which can be added to foods and beverages, and a process for their preparation.
It is another object of the present invention to provide a process for preparing a finely dispersed carotenoid suspension which avoids the use of organic solvents, elevated temperatures, high speed mixing, or high-shear mixing.
It is a further object of the present invention to provide a finely dispersed carotenoid suspension which are physiologically acceptable, and a process for their preparation.
These and other objects of the invention will be made apparent to those skilled in the art upon a review and understanding of this specification, the associated drawings, and the appended claims.
The process according to the invention is preferably used to prepare finely dispersed carotenoid suspensions for use to supplement foods and beverages with carotenoids, for use in coloring personal care products, foods and beverages, and to a process for their preparation.
Examples of carotenoids which can be used according to the invention are the known, available, natural or synthetic representatives of this class of compounds, for example actinioerythrol, astaxanthin, bixin, canthaxanthin, capsanthin, capsorubin, xcex2-8xe2x80x2-apo-carotenal (apo-carotenal), xcex2-12xe2x80x2-apo-carotenal, xcex1-carotene, xcex2-carotene, xe2x80x9ccarotenexe2x80x9d (a mixture of xcex1- and xcex2-carotenes), xcex3-carotene, xcex2-cryptoxanthin, lutein, lycopene, violerythrin, zeaxanthin, and esters of hydroxyl- or carboxyl-containing members thereof. The preferred carotenoids are lutein, xcex2-carotene, xcex2-cryptoxanthin, lycopene, zeaxanthin, canthaxanthin), and astaxanthin.
Emulsifiers that can used in the present invention include all cationic, anionic, and non-ionic emulsifiers that are also acceptable for ingestion or application in or to humans and animals on administration in the usual amounts and do not result in harm. Emulsifiers which can be used according to the invention include lecithin and lysolecithin, sucrose fatty acid esters, and poly glycol esters. In a preferred embodiment of the invention, sucrose fatty acid esters (SFAE) are used. Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are derived from sucrose and edible tallow, hydrogenated edible tallow, or edible vegetable oils. The total content of mono-, di-, and tri-esters is greater than 70%. Sucrose esters are food grade, odorless, nontoxic, and impart minimal flavor. They are also a non-irritant to the eyes and skin and so are suitable for pharmaceutical and cosmetic applications. Examples of SFAE particularly suited for use are sucrose stearate, sucrose palmitate, sucrose myristate, and sucrose laurate, for example, those sold under the product names S-1570, P-1570, LWA-1570, M-1695 and L-1695 by Mitsubishi-Kagaku Foods Corporation. Also preferred are poly glycol esters (PGE). Examples particularly suited for use are SWA-10D, L-7D, and L-10D available from Mitsubishi-Kagaku Foods Corporation.
The amounts of emulsifier(s) used are selected within a range which results in a finely dispersed, stable carotenoid suspension. In the liquid form of the concentrated product, the emulsifier comprises between about 1 to 40% by weight, and preferably between about 20% and about 30%; the carotenoid comprises between about 0.1 and about 20% by weight, and preferably between 5 and 10%; with water comprising the balance. Higher amounts of the emulsifier may be required if the carotenoid is supplied in a form containing an oil, whereas lower amounts generally will be sufficient if the carotenoid is supplied in the form of crystals.
An antioxidant can be added to the water and emulsifier mixture, to the concentrated product, and to the carotenoid prior to its addition to the water and emulsifier mixture. The antioxidant is used to increase the stability of the active ingredient to oxidative breakdown. The antioxidant if used is preferably dissolved together with the carotenoids in the water and emulsifier mixture. Examples of antioxidants which can be used include tocopherols, extracts of rosemary, ascorbyl palmitate, citric acid, ascorbic acid, BHA, and BHT. Other suitable antioxidants can also be used. The amount of antioxidant to be used depends on the particular antioxidant selected and the environment in which the carotenoid composition is to be used. The range of antioxidant is from about 0.01 to about 0.1 percent by weight, based on the weight of the carotenoid used in the composition.
The concentrated carotenoid products of this invention include from about 0.1 to about 20 percent by weight carotenoid, based on the weight of the concentrated product in liquid form, and between about 1 to about 35 percent by weight carotenoid, based on the weight) of the concentrated product in dry form.
Use of an anti-foaming agent prevents undesirable foaming of the composition during processing of the concentrated product and during the manufacturing of food or beverage items to which the concentrated product has been added. The amount of anti-foam agent to be used depends on the particular agent selected and the composition and processing conditions of the food or beverage processor which will be using the concentrated product. The range of anti-foam agent is from about 1 to about 10 ppm, based on the weight of the finished food or beverage product.
Optical clarity is a critical characteristic for many beverage compositions. Various fruit drinks, fruit juices and fortified water drinks have included terms such as xe2x80x9ccrystal clearxe2x80x9d and xe2x80x9cfreshxe2x80x9d to distinguish their image and marketability. Traditionally, this clarity has been difficult to achieve when carotenoids are added to these aqueous compositions. The use of emulsifiers and oil for the incorporation of carotenoids will commonly result in cloudiness of the final aqueous composition. The present invention utilizes, emulsifiers, preferably sucrose fatty acid esters (SFAE), and antifoam to disperse carotenoids in beverages and other water-based systems, while maintaining their optical clarity. For the purposes of this disclosure, optical clarity will be defined by the percent transmittance value determined at the wavelength of 800 nm in a 1 cm path length cuvette.
The processes to incorporate carotenoids into beverages that are in use today, utilize high shear mixing, organic solvents, high heating or oil and emulsifiers. Often times, the result of the carotenoid incorporation involves ringing of the carotenoid in the finished product. This characteristic is visually undesirable and requires considerable shaking of the beverage to redistribute the carotenoid. Many times the ring is adhered to the glass and becomes difficult, if not impossible to redistribute. The present invention utilizes emulsifiers, preferably sucrose fatty acid esters (SFAE), and antifoam to disperse carotenoids in beverages and other water-based systems, while maintaining their stability against ringing.
There are several factors that may affect the stability against ringing in aqueous compositions. These include the level of SFAE that is required to keep the carotenoid in the suspension; the hydrophilic/lipophilic balance (HLB) of the SFAE, which may affect the interaction of the carotenoids with the aqueous composition; and the inclusion level of the SFAE/carotenoid suspension, which may determine the stability against ringing. The inherent compositional difference of fruit drinks and fortified water may suggest that they will have differences in stability against ringing. These factors have been examined to determine whether there are preferred levels of SFAE and carotenoids that contribute to the stability against ringing.
Manufacturing Process
The carotenoid suspensions are prepared according to the invention by dissolving the emulsifier in a quantity of water at ambient temperature, and mixing the solution until the emulsifier has been dissolved in the water. If used, the alcohol and/or the antioxidant are/is added to the water and emulsifier solution. The anti-foam agent is also added. The particular order of addition of the alcohol, antioxidant, and anti-foam agent is not critical. The carotenoid is then mixed into the emulsifier solution until evenly dispersed. The resulting concentrated product is used by food and beverage processors to add either color or supplementation of carotenoids, or both, to their products by adding the concentrated product at an appropriate step in their manufacturing process. The concentrated product is a viscous liquid that may be dispensed by liquid metering devices commonly used by food and beverage processors. Alternatively, the concentrated product may be dried to form a dispersible powder. Preferred methods of drying include lyophilization, spray drying, and, most preferably, horizontal thin-film evaporation. In the experiments described herein, the compositions were dried until the total moisture content was less than 1%.